Efficacy of antihypertensive agents on central blood pressure (BP) in African Americans is not well studied. The authors report on an 8-week double-blind, randomized study of African American patients with stage 2 hypertension that compared brachial and central BP responses (substudy of 53 patients) to combination aliskiren ⁄ hydrochlorthiazide (HCTZ) and amlodipine monotherapy. Following a 1-to 4-week washout, initial therapy was aliskiren ⁄ HCTZ 150 ⁄ 12.5 mg (n=166) or amlodipine 5 mg (n=166) for 1 week, forced-titrated to aliskiren ⁄ HCTZ 300 ⁄ 25 mg or amlodipine 10 mg for 7 weeks. Mean seated systolic BP reductions from baseline was similar with both treatments ()28.6 mm Hg with aliskiren ⁄ HCTZ vs )28.2 mm Hg with amlodipine). In the substudy, significantly greater reductions in central systolic BP was observed with aliskiren ⁄ HCTZ vs amlodipine ()30.1 mm Hg vs )21.2; P=.031), although 24-hour mean ambulatory BP reductions between the two groups were similar. Central pressure is considered an important risk factor in African Americans, and these findings may suggest a new treatment option for these patients. J Clin Hypertens (Greenwich). 2011;13:366-375. Ó2011 Wiley Periodicals, Inc.African American adults have a greater prevalence of hypertension, an earlier onset, greater pressure-related end organ damage, and low blood pressure (BP) control rates compared with their white American counterparts (32% vs 23%).1,2 In addition, African Americans have diffuse macrovascular and microvascular dysfunction manifesting as increased stiffness of the carotid artery and aorta, 3,4 heightened-resistance artery constriction, and blunted-resistance artery dilation, 5 all of which correlate directly with end organ damage. 6,7 Although the prognostic value of brachial BP for future cardiovascular events has been well established, arterial stiffness and microvascular dysfunction significantly influence central BP, while brachial pressure is less influenced by these changes.
8The findings from the Strong Heart Study, which noninvasively determined central pulse pressure is more strongly related to vascular hypertrophy, extent of atherosclerosis, and cardiovascular events than is brachial BP, support the use of central pressure as a treatment target in clinical trials. 9 To date, findings from at least 7 longitudinal studies show that central BP is a stronger predictor of cardiovascular outcomes than brachial pulse pressure. 8,10 Although prospective data are needed, central BP may be pathophysiologically more relevant than peripheral (brachial) BP in the pathogenesis of cardiovascular disease.8 A recent study conducted in young (mean age, 21.7 years) and healthy (normotensive) African American and white men (mean age, 23.6 years) reported higher central BP and stiffer blood vessels in African American men compared with their white counterparts, signs that African American men are developing hypertension early and with few symptoms.
11Calcium channel antagonists and diuretics have long been preferred as an antihypertensive...